Explosion kills 6 British troops in Afghanistan

KABUL, Afghanistan — Six British soldiers were believed to be killed when an explosion struck their armored vehicle, marking the biggest loss of life for British forces in Afghanistan in years, officials in London said Wednesday.

The explosion a day earlier in the southern province of Helmand figured to renew calls for an earlier withdrawal from Afghanistan for international forces, which have faced increasing violence as they try to hand security responsibilities to Afghan forces before the end of 2014.

British Prime Minister David Cameron called it a "desperately sad day for our country," which has now lost 404 soldiers in the Afghan war, the highest death toll for a coalition country after the United States, which has lost 1,909 service members, according to the website icasualties.org.

The British defense ministry said in a statement that the soldiers were carrying out a patrol and that they were missing and presumed dead, indicating that coalition forces hadn't yet been able to retrieve the bodies. The BBC reported that initial assessments of the explosion said it had been carried out by the Taliban.

It was the deadliest incident involving British troops since 2006, when a plane crash killed 14 service members during an operation in southern Afghanistan.

Separately, in the neighboring province of Kandahar, a suicide bomber riding a motorbike set off his explosives Wednesday at a crowded marketplace, killing four civilians including two children, local officials said.

The mid-morning attack at Spin Boldak, on Afghanistan's border with Pakistan, also wounded eight people including a border policeman, said Javel Faisal, a spokesman for the Kandahar provincial government.

"Most of the victims were passengers travelling between Afghanistan and Pakistan," said Faisal. "There were no foreign soldiers nearby." He said the wounded were rushed to a hospital in Spin Boldak.

No group immediately claimed responsibility for the blast, which bore the hallmarks of a Taliban attack. Kandahar province is the birthplace of the Taliban movement and has long been one of the most restive areas of Afghanistan.

Afghan President Hamid Karzai described the incident as "a terrorist attack" carried out by the enemies of Afghanistan, and said it was "an act against both Islam and humanity."

Marine Gen. John R. Allen, commander of the U.S.-led coalition in Afghanistan, said in a statement that "the blatant murdering of Afghan civilians" must stop.

"The Taliban leadership needs to hold their own members accountable for their actions against the innocent," Allen said.